Obesity, defined as a body mass index (BMI) of 30 kg/m2 or greater, affects an estimated one-third of the adult population in the United States: 32% of men and 35% of women. Overall, 72% of men and 64% of women were either overweight (defi ned as a BMI between 25 and 29.9 kg/m2) or obese in 2007 to 2008.1 Obesity has numerous health-related consequences, including type 2 diabetes, cardiovascular disease, hypertension, and cancer. It contributes to obstructive sleep apnea, osteoarthritis, gallbladder disease, and nonalcoholic fatty liver disease. An estimated 65% of the incidence of type 2 diabetes in the United States is directly related to being overweight, with excessive weight accounting for up to two-thirds of diabetes-related deaths. In addition, obese adults clearly have a shortened life expectancy.2,3

Given current trends in overweight children and adolescents, without significant intervention nearly 90% of adults will be overweight or obese by 2030, and half will be obese.4 This would have devastating economic consequences for the healthcare system and the country as a whole, with healthcare costs related to overweight and obesity reaching between $860.7 and $956.9 billion and accounting for nearly one-fifth of all healthcare costs. That compares with the 9% in healthcare costs attributable to overweight and obesity in 1998.4,5 In a 2002 analysis of obesity-related healthcare costs, Sturm et al determined that the condition “outranks both smoking and drinking in its deleterious effects on health and health costs.”6 Figure 1 depicts the increased healthcare utilization and costs observed in 17,118 members of a large managed care organization. As the figure demonstrates, there is a direct correlation between BMI and healthcare resource utilization.7

Most people begin the trajectory toward increased costs of obesity during their working years. This results in a significant burden for employers, in terms of both increased medical costs and lost productivity. Durden et al evaluated health plan claims from self-insured employer plans in the United States between 2003 and 2005 and identified direct annual medical costs associated with overweight, obesity, and severe obesity (>40 kg/m2) of $147, $712, and $1977, respectively (Figure 2), while indirect costs resulting from paid sick leave were approximately $1400 for overweight or obese employees and $1500 for severely obese employees.8

Individuals who are obese, even those without any comorbid medical conditions, also have significantly reduced health-related quality of life, including physical health, psychosocial functioning, and emotional wellbeing, compared with normal-BMI individuals.9-13

Lifestyle, Medical, and Surgical Management of Obesity
Even a moderate loss of 5% to 10% of an individual’s body weight can have significant benefits in terms of health and disease risk, reversing existing obesity-related conditions such as diabetes, hypertension, and hypercholesterolemia, and reversing the trend toward development of comorbid conditions such as coronary heart disease, diabetes, stroke, and osteoarthritis.14,15

Guidelines for treating overweight and obese patients call first for lifestyle interventions of appropriate diet and exercise, although there is no evidence as to what type of diet or exercise regimen works best.16,17 Adding behavioral interventions such as food diaries, nutrition education, social support, and cognitive restructuring to diet and exercise has been shown to improve weight loss compared with diet and exercise alone.18,19

Still, such interventions are associated with only moderate weight loss of 5 to 8.5 kg (5%-9% of body weight) at 6 months, and a mean weight loss of 3 to 6 kg (3%-6% of body weight) over 48 months. Only about 20% of people who initially lose weight are able to maintain the weight loss for at least 1 year.20-23 After lifestyle interventions, pharmacologic and/or surgical management may be most effective in the obese, particularly the severely obese.16,17

Many of the currently Food and Drug Administration (FDA)–approved anti-obesity medications are approved for short-term use only (<3 months).24 These include the sympathomimetic drugs benzphetamine, diethylpropion, phendimetrazine, and phentermine, which have norepinephrine-like actions.25 In clinical practice, phentermine is the most commonly used medication and is often used beyond 3 months.26 Common adverse effects include an increase in pulse rate and blood pressure.

The only approved drug currently on the market for the long-term management of obesity is orlistat. This agent reduces intestinal digestion of fat by inhibiting the release of pancreatic lipase enzyme, which is required to break down fat for absorption. The most common side effects are oily fecal spotting, flatus, fecal urgency, and oily/fatty stools.25,27,28 Sibutramine, a selective serotonin and noradrenaline reuptake inhibitor, was available for the long-term treatment of obesity until its manufacturer pulled it from the market in October 2010 after clinical trial data suggested an increased risk of heart attack and stroke in elderly patients with known cardiovascular disease.29

There are several marketed drugs used off label for weight management; these include the anti-diabetic drugs metformin, exenatide, liraglutide, and pramlintide. The anticonvulsants topiramate and zonisamide have also been shown to produce significant weight loss.24 Bupropion, an antidepressant, has also been associated with weight loss in several studies.30 It is important to note that there are benefits and risk associated with the off-label use of these agents, and that their use may not be appropriate for all patients.

Developing anti-obesity drugs is difficult given the complexity of the metabolic system and the involvement of the central nervous system in appetite and satiety.31 In addition, the FDA has set a high bar for approval, including weight loss of at least 5% of baseline weight; no adverse cardiovascular effects; demonstrated loss of body fat, not just lean body mass; and low rates of psychiatric adverse events, abuse, dependence, and withdrawal effects.32

One of the first new anti-obesity drugs to come to the FDA, the cannabinoid receptor type 1 inverse agonist rimonabant, was rejected in 2007 because of a low incidence of depression with a possible increased risk of suicide seen in the clinical trials. Since then, the manufacturer withdrew its application to the FDA, took the drug off the market in Europe, and halted all clinical trials. The development of similar compounds (taranabant, otenabant, and SLV-319) has also been halted.32,33

In late 2010, the FDA declined approval for the selective serotonin stimulator lorcaserin, asking for additional information on its efficacy and safety. That same week, it declined approval for a phentermine/topiramate combination, citing concerns about the drug’s teratogenic effects and heart rate elevation. A few months later, it denied marketing approval for a naltrexone/bupropion combination pending cardiovascular outcome studies, despite an FDA committee recommendation that it be approved. 34,35 The FDA requirements for anti-obesity drugs have slowed the availability of weight loss agents, especially in the current regulatory climate.36

Bariatric Surgery for Obesity

In recent years bariatric surgery has emerged as a growing option for obese patients, particularly those with diabetes. The number of bariatric surgeries saw a dramatic increase in the early 2000s, driven in part by the introduction of minimally invasive procedures and by the emergence of bariatric surgical centers at most major hospitals. The incidence of the surgery has plateaued, at approximately 113,000 cases annually since 2007.37

There are several types of procedures, including adjustable laparoscopic gastric banding, sleeve gastrectomy, and Roux-en-Y gastric bypass; however, there is no agreement on how to determine the most appropriate option for patients.38 In a long-term study evaluating 4047 morbidly obese subjects, of whom 2010 underwent bariatric surgery and 2037 received conventional treatment, subjects were followed for up to 15 years.39 Maximum weight losses in the surgical subgroups were observed after 1 to 2 years, and weight losses from baseline stabilized after 10 years (Table).39 In patients undergoing surgery using the laparoscopic adjustable band, the average long-term (35 years) weight loss is 50% of excess body weight.18 However, 1 study reported that just 43% of patients had achieved and/or maintained this weight loss at 7 years.40 The procedures carry a complication rate of 7.6%, which has fallen from the 19.5% complication rate seen in 1993.37

The utilization of bariatric surgery has been limited, in part, by lack of insurance coverage. This is primarily driven by concerns that coverage will dramatically increase demand and costs. However, Kim et al found no significant increase in utilization after an employee-based healthcare system began covering the procedures.41 In addition, a study comparing outcomes between 587 patients who underwent bariatric surgery and 189 medically eligible patients denied coverage for the procedure found that after 3 years, 41% of those who did not have the surgery developed hypertension, 34% developed obstructive sleep apnea, 19% developed gastroesophageal reflux disease, 11% developed lipid disorders, and 9% developed diabetes, compared with less than 1% of a similar group who received the surgery and developed hypertension, obstructive sleep apnea, gastroesophageal reflux disease, or diabetes (3% developed lipid disorders).42 It was quite impressive to observe the number of obesity-related diseases that developed in the untreated patients.

Guidelines from the American College of Physicians recommend bariatric surgery for those with a BMI of 40 kg/m2 or greater, while guidelines from the American Society for Metabolic and Bariatric Surgery and the National Institutes of Health recommend bariatric surgery for those with a BMI of 35 kg/m2 or greater who also have an obesity-related disease, such as type 2 diabetes, coronary heart disease, or sleep apnea, and possibly in those with a BMI between 30 kg/m2 and 34.9 kg/m2.17,43,44 In contrast to these recommendations, the American Heart Association recently issued a new scientific statement clarifying its stance that bariatric surgery be reserved for patients who are severely obese and in whom no other approaches have been able to reduce their cardiovascular risk.45

In early 2011, the International Diabetes Foundation issued guidelines supporting the use of bariatric surgery in obese individuals with type 2 diabetes and the FDA approved lower BMI indications (30-40 kg/m2) for an adjustable gastric band used in laparoscopic gastric banding surgery.46,47

Economic Benefits of Obesity Management
The economic benefits of obesity treatment vary considerably depending on the intervention evaluated, the length of time of the intervention, whether the conditions were modeled or actually occurred, and the parameters evaluated, including comorbid diseases.

In a much-cited study in this area, Oster et al found that substantial health and economic benefits accrued with a sustained 10% loss of body weight, reducing the lifetime care costs of obesity-related diseases (hypertension, hypercholesterolemia, type 2 diabetes, cardiovascular disease, and stroke) by approximately $3300 to $3800 per person. It also led to an increased life expectancy of 2 to 7 months among men and 2 to 5 months among women; the increase was greater in younger individuals and in those with the highest baseline BMI.48 However, this model did not consider lifetime medical costs of other diseases, such as cancer, which tend to occur later in life. Since many cancers are related to obesity, these projections may be underestimates.

Weight loss has a profound effect on type 2 diabetes. A study of 458 patients with type 2 diabetes that modeled the economic effects of weight loss in this cohort found that just a 1% loss of body weight was associated with a 3.6% ($256) decrease in total health costs (P <.05) and a 5.8% ($131) decrease in diabetes-related costs (P <.01) compared with no weight loss.49

Physical activity interventions can be cost-effective. A study was conducted to estimate the lifetime cost-effectiveness of 7 public health interventions designed to promote physical activity in a simulated cohort of healthy Americans. The cost-effectiveness
ranged between $14,000 and $69,000 per quality-adjusted life-year (QALY) gained when compared with no intervention.50

Several studies evaluating orlistat concluded that the drug was cost-effective when added to lifestyle interventions. A review of 9 cost-effectiveness or cost-utility studies on orlistat concluded that using the drug as part of a weight-loss regimen in obese patients was “in the range of what is generally regarded as cost-effective,” but noted remaining uncertainty regarding weight loss sustainability, utility gain associated with weight loss, and extrapolations from transient weight loss to long-term health benefits.51

In 1 analysis comparing a low-calorie diet alone to a low-calorie diet in combination with orlistat over 1 year, van Baal et al found incremental costs per QALY of €17,900 for the low calorie diet–only intervention compared with no intervention, and €58,800 for the diet plus orlistat combination. Although the costs were lower when quality of life was considered, they were still significantly higher in the combination cohort.52

Ironically, although lifestyle interventions plus pharmacologic interventions are more effective in terms of weight loss, in some studies they do not appear more cost-effective over an individual’s lifetime. The explanation for this may lie in the fact that the risk of early mortality due to obesity declines, leading to an increased risk of age-related morbidities.53

The economic benefits of bariatric surgery appear to be more homogeneous. Cremieux et al evaluated the return on investment to commercial insurers who covered bariatric surgery in the United States. Given an initial investment of approximately $26,000 for open surgery and $17,000 for laparoscopic procedures, companies realized a return on their investment due to reduced obesity-related disease costs within 4 years for the former and 2 years for the latter.54 Currently, at our institution and at most Centers of Excellence in bariatric surgery, over 95% of bariatric surgeries are performed laparoscopically.

The cost-effectiveness of bariatric surgery compared with conventional treatment is particularly pronounced when evaluated in obese patients (BMI >35 kg/m2) with diabetes. 55-59 Ikramuddin et al assessed the cost-effectiveness of the Roux-en-Y procedure in obese patients with diabetes compared with standard medical management. They found that although mean lifetime direct medical costs for bariatric surgery were higher than those for medical management ($83,482 versus $63,722), the overall incremental cost-effectiveness ratio (ICER) of $29,676 per life-year gained and $21,973 per QALY met the standard guideline in the United States for cost-effectiveness ($50,000).57

There is also some evidence that the use of bariatric surgery to remit diabetes is cost-effective compared with conventional treatment even in patients with a BMI less than 35 kg/m2. Keating et al estimated an ICER of 16,600 Australian dollars for bariatric surgery in this population and concluded that the direct medical costs of the procedure would be recouped within 10 years due to savings incurred from medical treatment of type 2 diabetes.60

Role of Managed Care in Obesity Management
Despite the significant increase in medical costs resulting from obesity and evidence that some weight-loss approaches can be cost-effective, managed care has been somewhat resistant to covering obesity and its management as a sole disease state. Phone interviews conducted with health plans between November 2007 and March 2008 found that most rejected claims were coded solely for obesity, leading physicians to use other diagnosis codes in order to receive reimbursement.38 That may be changing, however. In 2005, Blue Cross and Blue Shield of North Carolina became the first health insurer to cover obesity as a stand-alone disease state and pay for nutritional counseling for both members and their children.38 Blue Cross/Blue Shield of Massachusetts began providing incentives to primary care physicians to chart the BMI of their pediatric patients and document any management approaches taken for those with a BMI greater than 85%.38 Kaiser Permanente put obesity at the top of its clinical priority list as early as 2006.61 Regardless of coverage, however, most health insurance organizations do provide education  about weight management and healthy living for members and their families.38

Employers tend to address obesity in the workforce through incentive or disincentive programs such as increases or decreases in health insurance premiums, wellness programs, and discounts and rebates, but few provide any incentives linked to childhood obesity.38

Public entities have been slower to recognize the condition as a separate disease state. A 2010 analysis found that just 8 state Medicaid programs covered all recommended obesity treatments for adults and just 10 reimbursed for obesity-related treatment in children.62 In 2011, the state of Arizona had plans to eliminate the Medicaid benefit for obesity treatment and charge an additional $50 to patients who do not lose weight after receiving a physician-developed weight-loss plan.63-65 Medicare covers obesity treatments in individuals with comorbid conditions related to obesity, such as cardiovascular, respiratory, and musculoskeletal disease. It also pays for bariatric surgery in beneficiaries with a BMI of 35 or greater and type 2 diabetes, hypertension, coronary artery disease, or osteoarthritis unresponsive to medical treatment. However, it does not cover obesity as a sole disease.65

State governments may be slightly more supportive of obesity treatments when it comes to their own employees. In 2011, for instance, Arkansas created a 4-year pilot program to provide insurance coverage for the treatment of morbid obesity for public employees, citing the “economic drain on the state” the condition poses, while Utah approved a bariatric benefit plan for state employees.63,64 Just 5 states, however, require that private insurers cover 1 or more treatments for obesity in the small group and/or individual markets.61

Plans and employers that do support weight management activities should consider minimizing member contributions. Several studies find that covered members are more willing to engage in weight management activities if they are fully covered and less so if they have to pay most of the cost themselves.66-68

Conclusion
The high incidence of obesity in this country results in substantial health, quality of life, and economic consequences. Without significant interventions in the coming decade, those consequences will worsen as the incidence of obesity grows, threatening to overwhelm the healthcare system. Traditional interventions including diet, exercise, and behavioral modification are usually insufficient for significant weight loss in those who are severely obese, and must be supplemented with medication and/ or surgery. Many of these approaches have been shown to be cost-effective given the long-term health effects of obesity.

However, with just 1 long-term medication available on the market and continued disappointments with compounds in development, it is doubtful that there will be new pharmacologic options on the market in the near future. Bariatric surgery provides another alternative, and results in greater weight loss compared with other treatments.

Patients must be selected carefully and be fully informed. Bariatric surgery is best done at a Center of Excellence. Determination of which bariatric procedure to perform needs to be individualized for each patient and weighed against potential complications. It is important that managed care organizations recognize the significant risk to their business posed by the high rates of obesity in this country, and provide interventions and incentives to address the challenge from a variety of perspectives.